Wednesday, September 28, 2011

Walton & Beckett Reticle

Walton & Beckett reticles are used primarily for counting particles, and in particular - asbestos dust particles or glass fibers.

Generally the fibers being counted are smaller than 5 microns in size. The circle on the reticle is divided into four by two diametrical lines scaled in units of 5 and 3 microns respectively. These are the critical measurements of fiber lengths and diameters used in asbestos fiber counting. The Walton and Beckett reticle has a series of shapes that have been designed to compare with fibers.